...“How many of youhave ever had chest pain?” All of us, right? At least that was the
case when we first began intense CrossFit workouts. A muscle ache in
the vicinity of the ribs or sternum would make you pause with: “What’s
that?” “Oh yea--those last two reps”--a superficial muscle pain...

Chest
pain is a whole lot different when it comes from a heart muscle
deprived of oxygen. Such pain may or may not involve the chest per se
and it even has a different name—“angina”. ...